Depigmented skin and phantom color measurements for realistic prostheses

PurposeThe purpose of this study was to test the hypothesis that regardless of human skin phototype, areas of depigmented skin, as seen in vitiligo, are optically indistinguishable among skin phototypes. The average of the depigmented skin measurements can be used to develop the base color of realistic prostheses. Methods and MaterialsData was analyzed from 20 of 32 recruited vitiligo study participants. Diffuse reflectance spectroscopy measurements were made from depigmented skin and adjacent pigmented skin, then compared with 66 pigmented polydimethylsiloxane phantoms to determine pigment concentrations in turbid media for making realistic facial prostheses. ResultsThe Area Under spectral intensity Curve (AUC) was calculated for average spectroscopy measurements of pigmented sites in relation to skin phototype (P=0.0505) and depigmented skin in relation to skin phototype (P=0.59). No significant relationship exists between skin phototypes and depigmented skin spectroscopy measurements. The average of the depigmented skin measurements (AUC 19,129) was the closest match to phantom 6.4 (AUC 19,162). ConclusionAreas of depigmented skin are visibly indistinguishable per skin phototype, yet spectrometry shows that depigmented skin measurements varied and were unrelated to skin phototype. Possible sources of optical variation of depigmented skin include age, body site, blood flow, quantity/quality of collagen, and other chromophores. The average of all depigmented skin measurements can be used to derive the pigment composition and concentration for realistic facial prostheses

Vascular complications following bladder drained, simultaneous pancreas-kidney transplantation: the University of Miami experience

Vascular complications remain a significant nonimmunologic source of pancreas allograft loss. From February 1993 through January 1998, we performed 98 simultaneous pancreas‐kidney transplantations (SPK) using pancreatic exocrine bladder drainage in patients with type 1 insulin‐dependent diabetes mellitus and end‐stage renal disease. They originally received quadruple immunosuppression, and since May 1997 triple immunosuppression protocol (tacrolimus, mycophenolate mofetil, and steroids). The patients' mean age was 37 years (range 24‐53 years), including 50 women and 48 men with a mean follow‐up of 42 months. The overall rate of vascular complications was 6% (5 patients). The vascular complications were as follows: late thrombosis of the Y with persistent pancreas allograft function (n = 1), rupture of a pseudoaneurysm of the superior mesenteric artery (PSMA) with an arteriovenous fistula (AVF) (n = 1), thrombosis of the splenic vein (SV) (n = 3), complete thrombosis of the superior mesenteric vein (SMV) and splenic vein (n = 1). The patient with PSMA underwent surgical correction of the AVF and PSMA with preservation of the allograft pancreas function. The other patient with late thrombosis of the Y‐graft required no treatment. All 3 patients with SV thrombosis were systemically heparinized followed by oral anticoagulation. The patient with complete thrombosis required surgical thrombectomy of the SMV and SV followed by heparinization and oral anticoagulation. All 6 patients including the 4 with thrombosis had preservation of the pancreas function. Serial pancreas ultrasound showed resolution and improvement with recanalization of the splenic vein and superior mesenteric vein in those patients with thrombosis. We describe our vascular experience with salvage of the pancreatic allograft function. Surgery seems to be the best treatment option in the case of AVF or complete thrombosis of the allograft. Intravenous heparin followed by oral anticoagultion could be a conservative approach for SV thrombosis